Diazotype photographic copying material adapted for wet development and for producing copied image in black color

ABSTRACT

A two-component diazotype photographic copying material for wet development and having a light-sensitive layer which contains at least one light-sensitive aromatic diazo compound and also contains at least one each of the three kinds of coupling components which are adapted to form a blue dye, a bluish-violet dye and a yellow dye, respectively, when said coupling components are made to react with said diazo compound, is capable of providing a copied image in a very clear black color when developed with an alkaline aqueous solution containing no coupling component.

United States Patent [72] Inventor Shlgealtl Toshida Kanagawa, Prefecture, Japan [21] Appl. No. 711,205 [22] Filed Mar. 7, 1968 [45] Patented Nov. 23, 1971 [73] Assignee Kabushiki Kaisha Ricoh Tokyo, Japan [54] DIAZOTYPE PIIOTOGRAPIIIC COPYING MATERIAL ADAPTED FOR WET DEVELOPMENT AND FOR PRODUCING COPIED IMAGE IN BLACK COLOR 2 Claims, No Drawings [52] US. Cl. 96/49, 96/75, 96/91 [51 Int. Cl G03c 5/34, G03c 1/58, G03c H54 [50] Field 01 Search 96/49, 75, 91

[56] References Cited UNITED STATES PATENTS 2,298,444 10/1942 Weissberger et a1 96/91 2,233,038 2/1941 Sus et a1 96/91 2,537,106 1/1951 Von Glahn et al 96/91 2,537,919 1/1951 Slii'kin 96/91 3,113,025 12/1963 Bialczok.... 96/91 3,248,220 4/1966 Van Rhijn 96/91 3,353,984 11/1967 Landau 96/91 X 3,387,977 6/1968 Habib et a1. 96/91 3 ,404,005 10/ l 968 Tobey 96/91 3,473,930 10/1969 Werner et a1. 96/91 FOREIGN PATENTS 896,453 1 H1953 Germany 96/91 Primary Examiner-Charles L. Bowers, .lr. Attorney-Woodhams, Blanchard and Flynn ABSTRACT: A two-component diazotype photographic copying material for wet development and having a light-sensitive layer which contains at least one light-sensitive aromatic diazo compound and also contains at least one each of the three kinds of coupling components which are adapted to form a blue dye, a bluish-violet dye and a yellow dye, respectively, when said coupling components are made to react with said diazo compound, is capable of providing a copied image in a very clear black color when developed with an alkaline aqueous solution containing no coupling component.

DIAZOTYPE PHOTOGRAPHIC COPYING MATERIAL ADAP'IED FOR WET DEVELOPMENT AND FOR PRODUCING COPIED IMAGE IN BLACK COLOR BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is concerned with a diazo-type photographic copying material, and more particularly, it relates to a diazo-type photographic copying material which has a lightscnsitive layer that contains three kinds of coupling components and which is adapted for wet development and adapted to produce a copied image which is black in color. Still more particularly, the present invention relates to a diazotype photographic copying material which has a light-sensitive layer that contains therein at least one light-sensitive aromatic diazo compound and also contains at least one each of the three kinds of coupling components which are adapted to form a blue dye, a bluish-violet dye and a yellow dye, respectively, when said coupling components are made to react with said diazo compound.

1. Description of the Prior Art Conventional diazo-type photographic copying materials which were adapted to produce copied images in a blackish color by wet development were such that each of them was provided with a light-sensitive layer on one surface thereof and that this light-sensitive layer contained no other reaction component but a light-sensitive aromatic diazo compound alone. A blackish dye was adapted to be produced from such an aromatic diazo compound when developed with a developer solution which contained, in general, phloroglucinol and/or resorcinol. More particularly, conventional diazo-type photographic copying materials adapted for wet development and for producing copied images in blackish colors were one-component type" copying materials which were so designed as to be developed by the use of a developer containing a coupling component. However, the coupling component which was contained in such a developer solution of the prior art was lacking, in itself, in stability, and the coupling component tended to become colored by being oxidized by the ambient air during the storage of or during the use of the developer solution. Besides, the copying material carrying a copied image which had been developed by the use of such a developer solution had the drawback such that the nonimage areas of the developed surface of the copying material became progressively stained during storage. For this reason, it was impossible to keep the developed copying material for an extended period of time in the state in which it carried a distinct and clear copied image.

SUMMARY OF THE INVENTION It is, therefore, the object of the present invention to obviate the aforesaid various drawbacks of the photographic copying materials of the prior art which arise from the inclusion of a coupling component in the developer solution, by the provision of a diazo-type photographic copying material having a light-sensitive layer which contains both a light-sensitive diazo compound and coupling components, instead of including the coupling components in the developer solution.

Therefore, the present invention contemplates the provision of a diazo-type photographic copying material for wet development which has a light-sensitive layer formed on one surface thereof, said light-sensitive layer containing therein at least one aromatic diazo compound expressed by the following chemical formula I and also containing at least one each of the following three coupling components, namely, a coupling component A which is expressed by the following chemical formula II and which is adapted to produce a blue dye due to the reaction of said component A with said diazo compound, another coupling component B which is expressed by the following chemical formula lll and which is adapted to produce a bluish-violet dye due to the reaction of said component B with said diazo compound and still another coupling component C which is adapted to produce a yellow dye due to the reaction of said component C with said diazo compound and which consists of any one or both of the two substances, namely, ethylenediamine-N'N-bisacetoacetamide and ethylenediamine-N-N'-bisacetoacetamide. This photographic copying material of the present invention provides a very clear copied image which is black in color, by being developed with an alkaline aqueous solution containing no coupling component whatsoever.

X represents an anionic acid radical.

wherein:

R and R represent radicals selected from the group consisting of alkyl radicals containing one to three carbon atoms and also of saturated heterocyclic radicals consisting of morpholinyl and piperidyl, and n represents an integer of 2 to 3.

NH III The aromatic diazo compound which is expressed by the aforesaid chemical formula I never develops a precoupling reaction with any one of the aforesaid coupling components A, B and C even when said diazo compound and these coupling components are contained jointly in the light-sensitive layer of the photographic copying material of the present invention, unless the copying material is subjected to development by the use of the developer solution according to the present invention. However, said diazo compound will react with all of these coupler components immediately after they are contacted by an alkaline aqueous solution which is the developer solution. The diazo compounds which are employed in the present invention include:

4-diazo-2,5-dimethoxy phenyl morpholine 4-diazo-2,5-diethoxy phenyl morpholine 4-diazo-2,5-dipropoxy ph'enyl morpholine and 4-diazo-2,5-dibutoxy phenyl morpholine. These diazo compounds are provided usually in the form of a double salt of such a diazo compound and a metal chloride.

There has been reported an instance where these aromaticdiazo compounds were used in the manufacture of one-component diazo-type photographic copying materials. There has never been reported to date an instance where such an aromatic diazo compound was used in the formation of thetwocomponent diazo-type photographic copying material having a light-sensitive layer which jointly contains such an aromatic diazo compound and the coupling components.

The coupling component A which is expressed by the aforesaid chemical formula II and which is used in the present invention is adapted to react with such an aromatic diazo compound as has been described above and, as a result, a blue dye is formed. This coupling component A includes:

2-hyroxy-3-naphthoic acid dimethylaminoethylamide 2-hydroxy-3-naphthoic acid dipropylaminoethylamide 2-hydroxy-3-naphthoic acid dipropylaminopropylamide 2-hydroxy-3-naphthoic acid diethylaminopropylamide 2-hydroxy-3-naphthoic acid dimethylaminopropylamide 2-hydroxy-3-naphthoic acid morpholinoethylamide 2-hydroxy-3-naphthoic acid morpholinopropylamide and 2-hydroxy-3-naphthoic acid piperidinopropylamide. Also, the coupling component B which is expressed by the aforesaid chemical formula III and which is used in the present invention is adapted to react with such an aromatic diazo compound as has been described above and, as a result, a bluishviolet dye is formed. This coupling component B includes:

l-biguanidino-2-naphthol I -biguanidino-4-naphthol l-biguanidino-5-naphthol and l-biguanidino-7-naphthol.

The total amount of the coupling components A and B which are included in the light-sensitive layer of the photographic copying material of the present invention is desirably such that the total number of moles of these two coupling components is in the range of from 0.5 to [.5 per mole of the diazo compound which is contained in said light-sensitive layer. The inclusion of these two coupling components in an amount greater than 1.5 moles will not only adversely affect the shelf life of the copying material, but also it will lead to a stained background of the developed black copied image which is carried on the surface of the copying material in such a way that the nonimage areas of the surface of the copying material will bear a yellow color.

The coupling component C which is used in the present invention and which is adapted to react with the aforesaid aromatic diazo compound to produce a yellow dye is selected from the group consisting of:

ethylenediamine-N-N-bisacetoacetamide and ethylenediaminc-N-N-bisacetoacetamide and the desirable amount of this coupling component C to be included in the light-sensitive layer is in the range of from 0.1 to 0.5 mole against 1 mole of the diazo compound which is contained in the light-sensitive layer of the copying material. It is to be noted also that this coupling component C which, instead of being included jointly with said diazo compound in the light-sensitive layer, is contained in the layer of precoating of :1 copying material will permit as good a black copied image to be produced as the one which is obtained from a copying material where this coupling component C is included in the light-sensitive layer thereof.

The aforesaid three kinds of coupling components A, B and C will react with said diazo compound with substantially the same coupling velocity. The copied image which is produced as the result of the coupling reaction between these coupling components and the diazo compound is that of a black color wherein both the portion of the maximum color density and the portion of halftone are identical in their color tone. Although the diazo-type copying material of the present invention is a two-component one, it hardly gives a colored image when developed with an ammonia gas, since the content of these three kinds of coupling components in the lightsensitive layer of this copying material is very small as compared with that of the copying materials intended for dry development which is effected by the employment of an ammonia gas. Therefore, in order to produce a satisfactory copied image on the copying material of the present invention by relying on the dry development process, it will be necessary to repeat the development operation several times. Furthermore, owing to the very limited amount of the coupling components contained in the light-sensitive layer of the copying material of the present invention, this copying material after the completion of the copying process will contain a substantially negligible amount, if any, of the residual coupling components that have not yet reacted. For this reason, it hardly occurs that the background areas of the image-carrying surface of the copying material of the present invention after the completion of the copying process becomes stained, during its storage for an extended period of time, as a result of the oxidation of the residual unreacted coupling components by the ambient air. Diazo-type photographic copying materials designed for wet development which have undergone the copying process, in general, tended to give rise to stained background areas on the image-carrying surface. For this reason, the employment of such a copying material for wet development in making an image-carrying copy which requires to be stored for an extended period of time has been considered inadequate. However, the image-carrying copy which is obtained by the employment of the diazo-type photographic copying material for wet development of the present invention permits its storage for a sufficiently long period of time.

The diazo-type photographic copying material which is obtained according to the present invention is intended to be developed by the use of an alkaline aqueous solution which contains no coupling component whatsoever. By developing the exposed copying material with this developer solution, here is obtained a clear black copied image. The alkaline component of the developer solution which can be applied to the present invention includes potassium carbonate, sodium carbonate, potassium hydroxide, potassium tetraborate, potassium metaborate or like substances and also their mixtures. The pH of the developer solution which insures the most satisfactory development of color is in the order of from l 1.0 to 12.5. While it has been stated that the light-sensitive layer of the photographic copying material according to the present invention contains the aforesaid aromatic diazo compound and also the aforesaid three kinds of coupling components A, B and C, it is to be noted that said light-sensitive layer can contain other additional agents. For example, the light-sensitive layer may contain a substance such as caffeine in an amount ranging from 0.5 to 1.0 percent by weight, or sodium mono, dior trisulfonate of naphthalene in an amount ranging from 0.5 to 2.0 percent by weight to serve as an agent adapted for improving the shelf life of the copying material. The light-sensitive layer may further contain a substance such as thiourea, cadmium sulfate and cadmium chloride in an amount ranging from 1.0 to 3.0 percent by weight to serve as an agent adapted for arresting the blotting of ink on the copying material. These percentages are given relative to the solution used for forming a light-sensitive layer.

DESCRIPTION OF THE PREFERRED EMBODIMENTS EXAMPLE 1 A solution for forming a light-sensitive layer and having the following composition was prepared:

Water 1000 cc. Concentrated sulfuric acid 8 cc. Caffeine l0 g. Naphthalene'Llfi-sodium trisulfonate 5 g. Z-hydroxy-J-naphthoic acid morpholinopropylamide [.5 g. l-biguanidino-7-naphthol HCl 2.5 g. Ethylencdiamine-NN-bisacetoacetamide L5 4-diazoQj-dibutoxyphenyl morpholine-zinc chloride double salt l l g. Saponin l g. Methylene Blue 0.05 g.

The aforesaid solution was applied onto one surface of a white sheet of paper which served as the support of a photographic copying material, and was dried. Thus, a diazo-type photographic copying material was obtained. An appropriate original was placed on the light-sensitive layer of this copying material, and the copying material was exposed to light through said original by the use of a copying apparatus provided with a fluorescent lamp of 60 w. The exposed copying material was then contacted by an alkaline aqueous solution containing 20 g. of potassium carbonate and 30 g. of potassium metaborate in 1,000 cc. of water to thereby develop color of the copied image. As a result, a bluish-black image was obtained.

EXAMPLE 2 A white sheet of paper serving as the support of a photographic copying material was precoated with a solution containing 20 g. of colloidal silica and 40 g. of polyvinyl acetate emulsion (having 50 percent of solid matter) in 1,000 cc. of water. Onto the resulting layer of precoat was applied the solution for forming a light-sensitive layer which was described in example 1 and was dried. Thus, a diazo-type photographic copying material was obtained. The image-carrying copy obtained by the use of this copying material had a white background, while the image portion as noted to provide a black copied image of a highly increased color density. This copy showed a high resistance to fading and permitted permanent storage.

EXAMPLE 3 A solution for forming a light-sensitive layer was prepared with a solution having the same composition described in example l, excepting that 4-diazo-2,5-diethoxyphenylmorpholine-zinc chloride double salt and 2-hydroxy-3- naphthoic acid dimethylamino propylamide were used in lieu of the 4-diazo-2,S-dibutoxyphenyl morpholinezinc chloride double salt and the 2-hydroxy-3-naphthoic acid morpholinopropylamide which were used in example 1, and also excepting that 3 g. of l-biguanidino-2-naphthol HCl was used in place of the 2.5 g. of l-biguanidino-7-naphthol HCl. The diazo-type photographic copying material obtained from this solution provided a copy which carried a black image having a highly increased color density.

EXAMPLE 4 The precoating solution used in example 2 and being admixed further with l g. of ehtylenediamine-N-N- bisacetoacetamide was precoated on one surface of a white sheet of paper serving as the support of a photographic copying material. On the layer of this precoat was applied a solution having the following composition:

Water i000 cc. Concentrated sulfuric acid 7.5 cc. Thiourea 10 g. Cadmium sulfate l0 g. Caffeine l0 g. Naphthalenc-l.3.6-sodium trisull'onate 5 g. Z-hydroxy-Il-naphlhoic acid morpholinocthylumide 1.4 g. l-biguflnidin07-nuphthol HCl 3 g. 4-diazo-2,S-dibutoxyphenyl morpholinc" zinc chloride double salt ll 5. Saponin l g. Methylene Blue 0.06 g.

and was dried. Thus, a diazo-type photographic copying material was obtained. After exposure to light, the copying material was developed by the use of an aqueous solution containing 3 percent potassium carbonate. As a result, a grayishblack copied image was obtained.

EXAMPLE 5 Onto one surface of a white sheet of paper serving as the support of a photographic copying material was applied a precoating solution which contained 120 g. of fine particles of corn starch (having a grain size of l-5p.), 40 g. of colloidal silica (with a grain size of l5p.), 80 g. of polyvinyl acetate emulsion (having a solid matter being 50 percent) and 0.9 g. of ethylenediamine-NN'-bisacetoacetamide, and was dried. Onto the layer of this precoat of the support was applied a solution for forming a light-sensitive layer and having the following composition:

Water I000 cc. Oxalic acid 8 g. Thiourea l0 5. Cadmium chloride 10 g. Caffeine l0 g. Naphthalenel ,3,6-sodium trisulfonate 5 g. 2-hydroxy-3-naphthoic acid diethylaminopropylamide L5 g. l-biguanidion-4-naphthol HCl 3 g. 4-diazo-2,5-dimethoxyphenyl morpholine'zinc chloride double salt l0 3. Saponin l g. Methylene Blue 0.06 g.

and was dried. Thus, a diazo-type photographic copying material was obtained. This copying material was then exposed to a light through an appropriate original which was placed on the surface of the light-sensitive layer thereof by the use of a copying apparatus provided with a fluorescent lamp of 60 w. The exposed copying material was developed with an aqueous solution of 5 percent potassium metaborate. As a result, a reddish-black copied image was obtained.

What is claim is: l. A process for making a black-line photoprint, which comprises the steps of;

exposing to actinic radiation a diazo-type photographic copying material on which is superposed an original, said diazo-type photographic copying material comprising a support and a light-sensitive layer on said support, said light-sensitive layer containing an acid stabilizer, at least one aromatic diazo compound having the formula:

R, and R each is a radical selected from the group consisting of alkyl radicals containing one to three carbon atoms or is a selected from the group consisting of morpholinyl and piperidyl, and n is an integer of from 2 to 3, B. another coupling component B adapted to react with said diazo compound to thereby form a bluish-violet dye and having the formula:

and

C. still another coupling component C adapted to react with said diazo compound to thereby form a yellow dye and consisting of at least one substance selected from the group consisting of ethylenediamine-N,N-bisacetoacetamide and ethylenediamine-N,N-bisacetoacetamide, and then treating said copying material with an aqueous alkaline developing solution free of coupling component to develop an image. 

2. A process for making a black-line photoprint according to claim 1, wherein the sum of the coupling components A and B contained in the light-sensitive layer of said copying material is in the range of from 0.5 to 1.5 moles per 1 mole of the diazo compound contained in the light-sensitive layer and the amount of the coupling component C contained in the light-sensitive layer of the copying material is in the range of from 0.1 to 0.5 moles per 1 mole of the diazo compound contained in the light-sensitive layer. 